21.3.1 Cubic Function (Dörr)

Dörr [25] proposed a polynomial relation between shear traction and slip which shows a limit if the slip is larger than a certain value  dt⁰ [Fig.21.13].

Figure 21.13: Cubic function for bond-slip (Dörr)

The formulation of this relationship is given by a cubic function:

$$\begin{cases} f_{\mathrm{t}} \left( 5 \left( \dfrac{\,\mathr... ...}} &\text{if $\,\mathrm{d}t\geq \,\mathrm{d}t^{0}$} \end{cases}$$ (21.23)

Unloading and reloading of the interface shear behavior is modeled using a secant approach.